Prefabricated insulation for HVAC ductwork and other fluid conduits

ABSTRACT

It is therefore the object of this invention to provide prefabricated insulation sheets, to fit around specific-sized perimeters of duct, which includes methods for anchoring sheets to surface to which they are applied, sealing jacket overlaps to adjacent jackets, and attaching overlapping longitudinal ends of sheets. This prefabrication replaces job-site cutting-to-length of sheets with flanges, as well as the additional step of sealing the exterior of jacket laps after installation, and the attachment of longitudinal ends of sheets with staples. It also provides a method of anchoring the end of sheets to the surface to which they are applied. The invention thereby both improves the installation method and the effectiveness of the attachment thereby improving productivity, reducing costs, and increasing the quality of the installation.

[0001] A method for prefabricating insulation for HVAC (heating,ventilation and air conditioning) duct insulation comprising thefollowing steps: Cutting sheets of duct wrap and a jacketattachment-flange; double-faced tape applied to the underside surface ofthis jacket attachment-flange and the underside surface of the factoryprovided jacket attachment-flange; installing tabs of jacket withdouble-faced tape on the non-flanged end; and installing metal orplastic prongs or anchors. This prefabrication eliminates many job-sitesteps, is safer, and improves quality and efficiency

CROSS REFERENCE TO RELATED APPLICATIONS

[0002] Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0003] Not Applicable

REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTINGCOMPACT DISK APPENDIX

[0004] Not Applicable

BACKGROUND OF THE INVENTION

[0005] This invention relates to the shop prefabrication of material forfield installation of insulation for HVAC ductwork and other fluidconduit or systems. More specifically, the invention relates toprefabricated sheets of jacketed flexible fibrous insulation that coversrectangular, square, round, and other shaped sections of heating,air-conditioning, and ventilation ducts and other fluid conduits, insideor outside of buildings.

[0006] Insulation of heating, air-conditioning, and ventilation ductworkand other fluid conduits or systems, inside and outside of buildings andin industrial processes, is necessary for energy conservation,temperature control, condensation control, sound reduction, fireprotection and other requirements. One form of insulating material forthe installation of insulation for these surfaces is flexible facedfibrous blankets manufactured in 4-foot wide and 50-, 75-, or 100-footlengths. The insulation is available in various thicknesses anddensities. It is faced with a laminated jacket of foil, fiberglassstrand reinforcement, and kraft paper or other membrane, and has atwo-inch facing attachment-flange on one side of the length.

[0007] The common procedure today is as follows: The insulation istransported to job site in rolls where it is cut to length, piece bypiece, as it is installed. A common procedure is, one workman rolls outthe material and makes cuts of the material on the floor near where thesystem to be insulated is located. The workman usually gets in akneeling position, or down on hands and knees, as it is otherwisedifficult to reach completely across the 4-foot width. Measurement ismade for the length to be cut on both edges of the material after it isunrolled onto the floor, and a straight edge is placed on the marks andthe cut is made with a knife. The straight edge is moved in two inchesfrom the end and another cut is made through insulation material, beingcareful to cut only through the insulation but not through thejacketing. The fibrous insulation is then pulled from the jacket on thetwo-inch width piece leaving a jacketing attachment-flange withoutinsulation.

[0008] The workman will then get up from the floor and deliver the cutpiece to the installing workman. This is repeated for each piecerequired. This job-site cutting method is very time consuming andstrenuous, subjecting the workman to the possibility of strains andsprains as well as exposing the workmen and other job site personnel toairborne fibers. These fibers may be both an epidermal irritant and arespiratory hazard. On some larger construction projects, such ashospitals, the insulation of ductwork may take many months to complete.

[0009] The applicator places the cut piece around the duct and theopposite longitudinal ends are pulled together, overlapping the flangefrom one end over the opposite end. The flange is then stapled to thejacket of the opposite end with a flare-type staple. Failure of theflare-door-type staple guns is common, and since many job sites are inremote locations, the failure of the staple gun delays work andincreases costs. After stapling is completed, the applicator applies apressure sensitive tape of similar type as the blanket jacket over thestaples and over the edge of the attachment-flanges, bothcircumferential and longitudinal joints. Care must be taken to make surethat every joint is sealed completely.

[0010] If the joints are not completely sealed on the insulationjacketing installed on duct such as air conditioning duct, whichoperates at a temperature lower than ambient temperature, moisture willenter the insulation making the insulation wet and ineffective. Thisresults in condensation drips that damage ceilings and interiors ofbuildings. Molds may result from this wet insulation and wet surfacesresulting in damage and an indoor air pollution problem.

[0011] For rectangular or square ducts having a width of over 24 inches,insulation anchors may be installed prior to installing the insulation.The anchors may be installed on the surface of the bottom of the duct oras required to hold the insulation tight to the surface.

[0012] The technique for installing insulation on heating,air-conditioning, and ventilation ductwork and other fluid conduit haschanged minimally over the last 30 to 40 years. Prior to that time,suitable pressure-sensitive tape was not available and a liquid adhesivewas brush applied under the overlap flanges or a mastic coating, with orwithout reinforcement, was used over all joints to achieve a seal. Eventhough this mastic type application takes considerably more time, it isspecified today by some engineers who do not trust that workmen willachieve a good seal with the pressure sensitive tape application.

[0013] Improved methods utilizing factory applied contact cements withrelease strip have been utilized for sealing molded fiberglass pipeinsulation jackets since the 1970's. Typical of such closures are U.S.Pat. Nos. 3,849,240: 4,022,248; 5,104,701; 5,234,520, 5,123,453 and5,736,211. All of these patents are for improved sealing of pipeinsulation and jacketing with the U.S. Pat. No. 5,736,211 for animprovement using an external band of jacket seal for butted edges. U.S.Pat. No. 5,104,701 is for a two-part application of non-tacky, moistureresistant strip and tape and adhesive systems that may be applied topipe and duct insulation. The application for duct insulation is appliedto the external surface of the jackets. My invention utilizes sealant onthe underside of jacket attachment-flanges. Major uses of these patentsare for improvement of pipe insulation and none address anyprefabrication of heating, air-conditioning, and ventilation ductwork,or other fluid conduit or system insulation.

[0014] A cutting device for cutting duct wrap, U.S. Pat. No. 5,086,680,addresses an improved method of cutting fibrous duct wrap blanket andutilizes a long handle to avoid the necessity of getting down on floorfor cutting. Although that device provides a method of cut off forblanket insulation, it may still be necessary to get on the floor formeasurement and marking. That device is a cut-off device, which will cutthrough both the insulation and jacketing, but it will notsatisfactorily cut through insulation only. The conventional means ofcutting away insulation from jacket would be required for fabricatingjacket attachment flanges.

[0015] In most construction trades, there is a shortage of skilledcraftsmen, and job-site productivity is low making costs high forjob-site installation. This results in prefabrication and unitizedconstruction being more widely used. Typical of such prefabrication areU.S. Pat. Nos. 5,285,609; 6,050,045; 6,311,446; and 6,318,044.Pre-engineered metal buildings are a good example of the utilization ofprefabrication and metal buildings are the most widely-used constructionfor one story warehouse, shop, and small to medium sized manufacturingfacilities.

[0016] There is therefore a need for improved productivity, costreduction and quality of installation of fibrous blanket ductinsulation.

BRIEF SUMMARY OF THE INVENTION

[0017] It is the object of this invention to provide a method forprefabricated insulation sheet for HVAC ductwork and other fluidconduits allowing much of the work historically done on the job site tonow be done in the shop. My invention eliminates some problems normallyencountered on the job site and allows the shop work to be done in amore productive manner and at a lower labor cost. The object of thisinvention is to provide prefabricated sheet that fits aroundspecific-sized perimeters of duct and includes installed tape forsealing jacket overlaps to adjacent jackets. The installation of thetape with release strips not only provides a way to easily seal thejacket without applying additional tape over the outside, it also addsrigidity to the jacket flanges before it is removed during application.This therefore eliminates the previous problems caused by the jacketflanges becoming folded or rolled under the insulation. This improvesthe installation method and effectiveness of seal thereby improvingproductivity, reducing costs, and increasing the quality ofinstallation. This is in addition to health benefits achieved throughthis invention through ergonomics and improved fiber control.

[0018] It is further an object of this invention to provide aninsulation sheet with affixed adhesive tabs to hold the longitudinal endin place on the surface of the duct. With the end anchored to thesurface, the entire sheet may be placed around the duct and thelongitudinal ends may be attached with ease.

[0019] It is further an object of this invention to provide aprefabricated insulation sheet with affixed metal or plastic prongs,tabs, or anchors thereby creating an easy means of attachment of theends of the sheet without the use of a staple gun and providing a meansof easily attaching the sheet to the surface of the duct. Metal orplastic prongs, tabs, or anchors, through the jacket on thenon-attachment flange end or other locations, facilitates the attachmentof the flange end in an overlapping position, and in other locationssecures insulation to the surface to prevent sagging. This inventionprovides means to accomplish easy and quality installation of flexiblefibrous insulation with jacket to HVAC ductwork and other fluidconduits.

[0020] These objectives and other objectives of this invention are thusaccomplished by providing attachment-flanges with contact adhesive withrelease strips on one end and on one side of the insulation sheet.Jacket tabs with contact adhesive with release strips on thenon-attachment flange end facilitates the attachment of the end to thesurface onto which it is positioned. These insulation sheets areinstalled onto ductwork in succession thus providing complete insulationof the entire duct system.

BRIEF DESCRIPTION OF DRAWINGS

[0021] The present invention will be better understood when viewed withthe following drawings wherein:

[0022]FIG. 1 is an isometric view of a typical roll of flexible fibrousblanket insulation with jacket facing, for reference showing the jacketflange on one side of the roll;

[0023]FIG. 2 is an isometric view of a prefabricated piece of flexiblefibrous blanket insulation with jacket facing attachment flanges on onelongitudinal end and on one circumferential side, both with pressuresensitive contact adhesive strips with release strips, and withjacketing facing attachment tabs with pressure sensitive contactadhesive strips with release strips on the non-flanged longitudinal end;and with installed metal prongs in jacketing of the longitudinalnon-flanged end;

[0024]FIG. 3 is an isometric view of attachment of the longitudinalnon-flanged end of a prefabricated piece of flexible fibrous blanketinsulation to a section of HVAC duct by attachment of jacketing tabswith pressure sensitive contact adhesive strips and release strips.

[0025]FIG. 4 is an isometric view of a further step of securing theprefabricated piece of flexible fibrous blanket insulation to a sectionof HVAC ductwork by impaling the longitudinal flanged-end over the metalprongs located on the non-flanged longitudinal end, sealingjacket-flanges and bending the metal prongs tight against thejacket-flange.

[0026]FIG. 5 is an isometric view of a further step of installing asecond prefabricated piece of flexible fibrous blanket insulation to asection of HVAC ductwork with the same installation sequence and thesecond prefabricated piece of flexible fibrous blanket insulation isabutted to the first piece along the circumferential edge and the jacketflange with the pressure sensitive contact adhesive and release stripoverlapping the adjacent piece. The release strip is removed from thecircumferential pressure sensitive adhesive strip and the seal iscomplete as the sheet is wrapped around the ductwork section.

[0027] Many variations of the above invention may be apparent to thoseskilled in the art from the reading of the description, which isexemplary in nature. Such variations are embodied within the spirit andscope of this invention as measured by the following appended claims.

DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

[0028] The subject invention has application wherever the insulation ofduct or other fluid conduits is necessary using flexible fibrous blanketinsulation with jacket. However, the invention as seen in FIGS. 1-6 willbe described in the embodiment of insulation on a straight section ofround HVAC ductwork. The invention can be used in the insulation ofother shaped surfaces of ductwork or conduits including various fittingshapes.

[0029] As best seen in FIG. 1, insulation material 1 with jacket 2 frommanufacturers is in rolls and is equipped with one jacketattachment-flange 3 that may be partly rolled under or folded.

[0030] As best seen in FIG. 2, a sheet of insulation material 1 withcircumferential jacket flange 4 and with longitudinal jacket flange 5has been cut into length to fit around the perimeter of a section ofstraight duct .

[0031] As best seen in FIG. 2, a tape member 8 having an adhesivebacking 9 which is typically covered by a conventional release paper 10is secured to the inner surfaces of the longitudinal jacket flange 5 andalso is secured to the inner surfaces of the circumferential jacketflange 4 resulting in the circumferential jacket flange 4 to be smooth,stiffened and unrolled.

[0032]FIG. 2 shows the release paper 10 is partially removed from endsof tape members 8 at the corner where circumferential 4 and longitudinal5 jacket flanges intersect. As best seen in FIG. 2, attachment tabs 12are shown with the conventional release paper 10 partly removed and thetabs affixed to the jacket of the non-flanged longitudinal end 13 withthe remainder of the tabs not affixed to the jacket 2 and with theadhesive strip and release strip in place.

[0033] As best seen in FIG. 3 a sheet of insulation material I has beenplaced partially around duct section 14 is seen with the non-flangedlongitudinal end 13 attached to the duct section 14 by removing therelease strips from the adhesive on the attachment tabs 12 and adheringthe attachment tabs 12 to the duct section 14 with the metal or plasticprongs 11 in place.

[0034] As best seen in FIG. 4 the sheet of insulation with longitudinaljacket-flange end 5 has been placed around the duct section 14 andrelease strips have been removed from the longitudinal jacket-flange 5and the longitudinal jacket-flange 5 is adhered to the non-flangelongitudinal end 13 of the piece and the metal prongs 11 are installedin the jacket 2 of the non-flanged longitudinal end 13 and are impaledand laid down on the longitudinal jacket-flange 5.

[0035] As best seen in FIG. 5, one cut sheet of insulation with jacket 2is in place around the perimeter of a section of straight duct 14 withlongitudinal end jacket flange 5 overlapping non-flange longitudinal endwith the end of attachment tabs 12 showing and with the attachmentprongs 11 bent over in place. The depiction illustrated in this view isaccomplished after the release strip has been removed and thelongitudinal flange adhered to the non-flange end jacket.

[0036] As best seen in FIG. 5 a second cut sheet of insulation 1 withjacket 2 has been placed partially around duct section 14 is seen withthe non-flanged longitudinal end 13 attached to the duct section 14 byremoving the release strips from the adhesive on the attachment tabs 12and adhering the attachment tabs 12 to the duct section 14 with themetal or plastic prongs 11 in place is abutting the first piece appliedwith the circumferential jacket-attachment-flange 4 partially adhered tothe jacket 2 of the first piece and the release 10 partly removed foradhesive strip 9 on the longitudinal end jacket flange 5.

[0037] Successive pieces of prefabricated flexible fibrous blanketinsulation are applied to ductwork as depicted in FIGS. 1-5 completingthe entire ductwork system insulation.

[0038] Many variations of the above invention may be apparent to thoseskilled in the art from the readings of the description, which isexemplary in nature. Such variations, may include installing tape withrelease strip partially removed on outside surface of flanges andvariations are embodied within spirit and scope of this invention asmeasured by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

[0039] This describes a method and system for insulating rectangular,square, round, and other shaped sections of heating, air-conditioningductwork, and other fluid conduits, inside and outside buildings, usingprefabricated fibrous duct insulation which is quick and easy toinstall. For wrapping ducts, a prefabricated system of sheets ofinsulation, with jacket, with longitudinal and circumferential jacketflanges that have double-faced tape with release strip on the undersideof flanges for pressure adhesion construction is provided. The jacketflanges are for attaching the two longitudinal ends together and alsofor attaching the circumferential jacket flange to the adjacentinstalled piece. Included are adhesive tabs for attachment of non-flangelongitudinal end to surface of duct. Also provided is a mechanicalattachment provision consisting of pronged metal or plastic tabs oranchors for the attachment of the two overlapping longitudinal endstogether and/or anchoring the blanket to the surface of the duct.Prefabricated pieces are plastic sheet shrink-wrapped to minimize fiberdisbursement during transportation and job-site handling.

What I claim as my invention is:
 1. Prefabricated insulation for HVACductwork and other fluid conduits. (a) A plurality of prefabricatedsheets of flexible fibrous insulation blanket with jacket with eachsheet to fit around the perimeter of specific-sized ductwork, with eachsheet having one longitudinal edge jacket-flange and one circumferentialedge jacket-flange with self sealing tape with release strips on boththe longitudinal and circumferential jacket-flanges undersides. (b) Aplurality of prefabricated sheets of flexible fibrous insulation blanketwith jacket to fit around the perimeter of specific-sized ductwork, witheach sheet having jacket tabs with self-sealing tape with releasestrips, with release strip removed from ½ the length of each tab with ½the length of each tab adhered to the non-flange end of the sheet. (c)The plurality of prefabricated sheets of flexible fibrous insulationblanket with jacket to fit around the perimeter of specific-sizedductwork, with each sheet having metal and/or plastic attachment prongs,pins, or anchors in the non-jacket-flange longitudinal end jacket and orin other locations on the sheet, such as locations to prevent sagging inthe blanket sheets.
 2. A method of installing a plurality ofprefabricated sheets of flexible fibrous insulation blanket with jacketonto HVAC ductwork or other fluid conduits comprising: (a) providing aprefabricated insulation for HVAC ductwork and other fluid conduitshaving one longitudinal edge jacket-flange and one circumferential edgejacket-flange with self-sealing tape with release strips on both thelongitudinal and circumferential jacket flanges undersides; i) with eachsheet having jacket tabs with self-sealing tape with release strips,with release strip removed from ½ the length of each tab with ½ thelength of each tab adhered to the non-flange end of the sheet; ii) witheach sheet having metal or plastic attachment prongs, pins, or anchorsin the non-jacket-flange longitudinal end jacket and or in otherlocations on the sheet, such as locations to prevent sagging in theblanket sheets. b) removing the release strips from the self-sealingadhesive tabs on one sheet, placing the sheet onto the ductwork andadhering the tabs to the ductwork surface. (c) placing said sheet aroundsaid ductwork and removing the release strips from the self-sealingadhesive on the longitudinal end jacket-flange of the sheet and adheringthe jacketing-flange to the abutting jacket surfaces. (d) impaling themetal or plastic prongs, pins, or anchors on the sheet through theoverlapping jacket-flange and securement of said jacket-flange byfolding or attaching the metal or plastic prongs or anchors, tightagainst the surface of the jacket-flange or other securement on otherjacket surface. (e) applying additional prefabricated sheets insuccession onto ductwork or fluid conduit with the circumferentialjacket-flange overlapping the circumferential end of the previouslyapplied sheet removing the release strip from the circumferentialjacket-flange and adhering the circumferential jacket-flange to theabutted sheet jacket to accomplish complete insulation of ductwork orconduit system.